None of this is real. The rocks, the stars, the enormous transmitter standing upright like a needle. It’s all a mixture of pixels presented by the Oculus Rift. As I stand on Mars, I urge my senses to surrender to the illusion. I long to be Matt Damon, growing potatoes in a makeshift greenhouse. In reality, I’m standing in a “scene” created by Linden Lab for Sansar, a new virtual-reality platform. A few feet to my left is chief executive Ebbe Altberg, standing in a dinosaur outfit. His avatar waves goofily, breaking my dream within a dream. I can’t help but sigh, accepting once more that I’m just a virtual sightseer.